Pierre, thanks so much. We're learning about the heroes of the tragedy that swooped into the chaos and carried people to safety. Abc's jim avila is there in washington, at the navy yard, where the shooting took place. Good morning, jim. Reporter: Good morning, robin. Amidst the horrors of monday morning, glimpses of bravery. Today, we hear from those heroes. It was an amazing sight, with a gunman on the loose, a helicopter hovers into range, on purpose. Not knowing if someone might fire on them. We were very aware that we were going into that environment. We wanted to get to the people as quickly as we could. Reporter: From just above the building tops, lowering a rescue basket to tactical police below. Pulling civilians to safety. One of them injured. You don't want to swing them out of the basket. Reporter: As the pilots hover, and sergeant dave tolson hovered the basket, his partner leans out of the copter, an m-16 on his shoulder, providing cover. How many times have you had to have a rifle in your hand while you're doing a rescue? A rifle for a rescue, this would be a first. Reporter: Inside the building on the fourth floor, where the gunman was firing away, john weaver could not believe his eyes. When he looked at her, he looked straight at her. Clinched that jaw and just, boom. Reporter: Another hero, not a first responder. But the man who witnessed the gunman's first shots and ran through the hallways to sound this alarm. I started running down the stairs, yelling at people to run. A man was killing people with a shotgun. Reporter: And to weaver, it all seems so unimaginable. The people killed. They don't deserve to die a horrible death like they did. It was tragic. Reporter: John weaver was still shaking when I spoke with him. So deep are his wounds. He can only say, he wish he could have done more. Robin? Jim, thank you very much.

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